It's working again. For now. In low the car would not move. It was like having a transbrake. Only had 3rd and reverse. Checked the linkage and then took it for a little drive. Started in 3rd each time then I slowed to about a 5 mph roll and then pulled the shifter back in low. It barked the tires for a split second when the wheels locked up and then it broke free. Appears to work normally now. I think it was either the governor was stuck or the 2-3 shift valve in the valvebody was stuck.
Hopefully it will get me through the rest of the summer/fall. Cruises, Drive Inn nights, etc. I will pull it and rebuild it, add a shift kit and a new converter. Was going to have to pull it anyway to replace the front seal. If it doesn't last until then I will do it when it goes.